000174663 001__ 174663
000174663 005__ 20190316235307.0
000174663 0247_ $$2doi$$a10.5075/epfl-thesis-5293
000174663 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis5293-7
000174663 02471 $$2nebis$$a6791841
000174663 037__ $$aTHESIS
000174663 041__ $$aeng
000174663 088__ $$a5293
000174663 245__ $$aMiniature Mobile Systems for Inspection of Ferromagnetic Structures
000174663 269__ $$a2012
000174663 260__ $$aLausanne$$bEPFL$$c2012
000174663 300__ $$a165
000174663 336__ $$aTheses
000174663 520__ $$aPower plants require periodical inspections to control  their state. To ensure a safe operation, parts that could  fail before the next inspection are repaired or replaced,  since a forced outage due to a failure can cost up to  millions of dollars per day. Non-Destructive Testing (NDT)  methods are used to detect different defects that could  occur, such as cracks, thinning, corrosion or pitting. Some  parts are inspected directly in situ, but may be difficult to  access; these can require opening access holes or building  scaffoldings. Other parts are disassembled and inspected in  workshops, when the required inspection tools cannot be  moved. In this thesis, we developed innovative miniature mobile  systems able to move within these small and complex  installations and inspect them. Bringing sensors to  difficult-to-access places using climbing robots can reduce  the inspection time and costs, because some dismantling or  scaffolding can be eliminated. New miniature sensors can help  to inspect complex parts without disassembling them, and  reduce the inspection costs, as well. To perform such inspections, miniature mobile systems  require a high mobility and keen sensing capabilities. The  following approach was used to develop these systems. First,  different innovative climbing robots are developed. They use  magnetic adhesion, as most structures are made of  ferromagnetic steel. Then, vision is embedded in some of the  robots. Performing visual inspections becomes thus possible,  as well as controlling the robots remotely, without viewing  them. Finally, non-visual NDT sensors are developed and  embedded in some of the robots, allowing them to detect  defects that simple vision cannot detect. Achieving the  miniaturization of the developed systems requires strong  system integration during these three steps. A set of  examples for the different steps has been designed,  implemented and tested to illustrate this approach. The Tripillars robots, for instance, use caterpillars, and  are able to climb on surfaces of any inclination and to pass  inner angles. The Cy-mag3Ds robots use an  innovative magnetic wheel concept, and are able to climb on  surfaces of any inclination and to pass inner angles, outer  angles and surface flips. The Tubulos robots move in tubes of  25 mm diameter at any inclination. All robots embed the  required electronics, actuators, sensors and energy to be  controlled remotely by the user. Wireless transmission of the  commands signals allows the systems to maintain their full  mobility without disturbing cables. Integrating Hall sensors  near the magnetic systems allows them to measure the adhesion  force. This information improves the security of the robots,  since when the adhesion force becomes low, the robots can be  stopped before they fall. The Tubulo II uses Magnetic  Switchable Devices (MSDs) for adhesion. An MSD is composed of  a ferromagnetic stator and one or more moving magnets; it has  the advantage of requiring only a low force to switch on or  off a high adhesion force. MSDs have the advantage of being  easy to clean of the magnetic dust that is present in most  real environments and that sticks strongly to magnetic  systems. As an additional step toward inspection, a camera is  embedded on the Cy-mag3D II and the Tubulos. It  allows these robots to inspect visually the structures the  robots move in, and to control them remotely. The perspective  of a climbing robot in an unknown environment is often not  enough to give the user a sense of its scale, and to move  efficiently in it. A distance sensor is designed and embedded  on the Cy-mag3D II, which increases the user's  perception of the environment substantially; Finally, an innovative miniature Magnetic Particle  Inspection (MPI) system was developed to inspect turbine  blades without disassembling them. An MSD is used to perform  the required magnetization. The system can automatically  inspect a flat surface, performing all the required steps of  MPI: magnetize, spray magnetic particles, record images under  UV light and demagnetize. Thanks to the strong integration  and miniaturization, the system can potentially inspect  complex parts such as steam turbines.
000174663 6531_ $$aInspection robot
000174663 6531_ $$aClimbing robot
000174663 6531_ $$aMobile robot
000174663 6531_ $$aMagnetic adhesion
000174663 6531_ $$aVision
000174663 6531_ $$aNon-Destructive Testing
000174663 6531_ $$aIntegration
000174663 6531_ $$aRobot d'inspection
000174663 6531_ $$aRobot grimpant
000174663 6531_ $$aAdhésion magnétique
000174663 6531_ $$aVision
000174663 6531_ $$aIntégration
000174663 6531_ $$aContrôle Non Destructif
000174663 700__ $$0242147$$aSchoeneich, Patrick$$g155115
000174663 720_2 $$0240589$$aMondada, Francesco$$edir.$$g102717
000174663 8564_ $$s50152878$$uhttps://infoscience.epfl.ch/record/174663/files/EPFL_TH5293.pdf$$yTexte intégral / Full text$$zTexte intégral / Full text
000174663 909C0 $$0252016$$pLSRO
000174663 909CO $$ooai:infoscience.tind.io:174663$$pSTI$$pthesis$$pthesis-bn2018$$pDOI$$qDOI2$$qGLOBAL_SET
000174663 918__ $$aSTI$$cIMT$$dEDPR
000174663 919__ $$aLSRO1
000174663 920__ $$b2012
000174663 970__ $$a5293/THESES
000174663 973__ $$aEPFL$$sPUBLISHED
000174663 980__ $$aTHESIS